What exactly is your error?
Have you been using this in production and it's suddenly failing? Or are you developing your programs now and having difficulties connecting?
Your question and response are too vague to give you any sure answers.
When I read your question, it appeared that this was a development issue. If your people are developing from scratch, with the little info you provided, it is difficult to make any suggestions. However, the samples IBM provides can be used as a resource for developing production code. If your people are in the development phase and using these samples, I felt I might be able to make a few suggestions on what the issue might be. If they are in development and have not tried to use the samples, I would strongly recommend they give the samples a look if they cannot connect.
If you provide more info on the actual errors that are occuring and whether the code has ever worked, I'll try to help.